IRA is a game of two teams based on one team getting the other teams word before the time runs out.
The two teams are the IRA and the Black & Tans. The IRA think up of a word and give one letter of the word to each member of their team and they run off and hide. It is the Black & Tans job to catch them and beat the letter out of them. While it may seem to be a very violent game it is not. As soon as a player gives up their letter the beating stops and the Black & Tans have to move on. Once the word has been found or the time has run out the game ends.
This game's names are primarily Irish as they reflect the War of Independence but they can be easily changed to avoid upsetting people or to suit the game to another country.
There is an optional set of rules known as traitors rules. What these mean is that when you give up your letter you join the Black & Tans and continue playing.